P28GANK exists in human hepatocytes. Generally, P28GANK is over-express in HCC compared with normal liver tissues. The coding frame of p28GANK contains 226 amino acids with 6 repeating ankyrin sequence (Gene ID: 5716), and molecular weight is 25 kDa. The inventor has prepared a rabbit-anti-human polyclonal antibody against p28GANK useful for pathological diagnosis of hepatocarcinoma. The polyclonal antibody has been disclosed in the Chinese patent ZL03116825.6, the title of which is “Antibody against p28 for the differentiation and diagnosis of hepatocarcinoma and its preparation”.
P28GANK has been reported to promote tumor progression mainly through the regulation of endoplasmic reticulum stress (ER stress), NF-κB, P53 and Rb signal pathways. P28GANK directly binds to RelA/NF-κB to accelerate the nuclear-export of NK-κB; p28GANK can bind to ubiqutin ligase MDM2 to mediate the ubiquitination-degradation of p53; p28GANK can bind to tumor-suppression protein Rb and drive the phosphorylation inactivation of Rb and the releasing of the nuclear transcription factor E2F-1, thus accelerate the cell cycle (See: Li H, et al. Use of adenovirus delivered siRNA to target oncoprotein p28GANK in hepatocarcinoma. Gastroenterology 2005; 128:2029-2041; Dai R Y, et al. p28GANK inhibits endoplasmic reticulum stress-induced cell death via enhancement of the endoplasmic reticulum adaptive capacity. Cell Research 2009 November; 19(11):1243-1257 Chen Y, et al. Oncoprotein p28 GANK binds to Re1A and retains NF-kappaB in the cytoplasm through nuclear export. 2007 December; 17(12): 1020-9).
It has been reported that the main factors affecting the prognosis of hepatocarcinoma were the tumor size and the vascular invasion, and usually accompanied by its multiple feature. At present, more and more researches show that the prediction of the recurrence of hepatocarcinoma still needs more effective prognostic factors. Previous researches show that p28GANK possibly play an important role in hepatocarcinoma progression, but the regulation mechanism of p28GANK is still unclear. Up to now, there isn't any report discloses that the expression level of p28GANK can be directly used as a prognostic factor for hepatocarcinoma recurrence and metastasis, as well as individual treatment index for hepatocarcinoma patients.